1. Field of the Invention
The present invention relates to a remote-controlled rearview mirror assembly such as automobile door mirror assembly, of which the mirror is supported tiltably relative to the housing thereof, and more particularly, to an improved and novel electrical remote-control mirror assembly, of which the mirror can be tilted down quickly and easily at any time for viewing the rear wheel and its vicinity of the car.
2. Prior Art Statement
An electrical remote-control automobile mirror assembly is disclosed in, for example, the U.S. Pat. No. 4,555,166, of which the mirror is supported tiltably relative to the housing thereof and can be turned vertically and horizontally by means of remote-controlled motors.
FIGS. 1 and 2 show an example of the well-known electrical remote-control mirror assembly of this type.
FIG. 1 is a front view showing the drive unit from which the mirror body is removed, the casing 1 of the drive unit being partially cut off. FIG. 2 is a sectional view taken along the line II--II, showing the drive unit on which the mirror body is attached.
Two axes X-X' and Y-Y' perpendicular to each other are set as shown in FIG. 1. There is provided at the intersection O of these axes a ball-and-socket joint 2 by which the mirror body 3 is tiltably supported as shown in FIG. 2. The reference numeral 4 indicates a mirror proper.
As shown in FIG. 1, plungers 5 are provided on the axes X-X' and Y-Y', respectively. The plunger 5 has provided at the end thereof a ball-and-socket joint 6 coupled to the mirror body 3, as shown in FIG. 2. The plunger 5 has formed axially therein a recess 7 in which a projection 8 provided on the drive casing 1 is engaged against axial pivoting of the plunger 5, and it has fitted thereon a gear 9 at the last speed reduction step. The gear 9 is rotated by a motor 10 by means of a speed reduction gear group 11.
As described above, the plunger 5 is blocked against axial pivoting and has formed on the outer circumference thereof a thread which is in mesh with the gear 9. Thus, as the gear 9 is rotated, the plunger 5 is axially driven to tilt the mirror body 3.
The adjusting range of the angular position of the mirror 4 tilted by the above-mentioned drive unit (see FIGS. 1 and 2) is so set as to cover the necessary range for an ordinary driving of the car on the road. Also, the tilt speed of the mirror body 3 is limited to such an extent that it can be adjusted with an accuracy required in practice. This is because if the mirror body is tilted too quickly, it is rather difficult to adjust the tilt angle to a desired one.
However, in any special driving of the car, for example, when moving the car backward in the vicinity of a road edge or in the direction of its width, it is desired to have a vision of the rear wheel and its vicinity, of which the image is viewed as reflected by the door mirror (this vision will be referred to as "reflected image" hereinafter).
FIG. 3 is an explanatory drawing showing the viewing, by means of a door mirror, of the rear wheel and its vicinity.
The point "Eye" in FIG. 3 is the position of the driver's eyes. In the ordinary driving of a car, the door mirror posture (theoretically a door mirror angle relative to the road surface, or practically a door mirror angle relative to the car body; this will be referred to as "mirror angle" hereinafter) is so adjusted as to view the reflected image within the angular range .music-flat. in FIG. 3 for the purpose of knowing the position of a car behind or the like.
When moving the car backward in the vicinity of a road edge, the reflected image within the angle .phi. in FIG. 3 can desirably be viewed by tilting down the mirror body. To this end, it is required that the rear wheel should be within the angular range .phi. and that the road surface over the distance L necessary for knowing the position of the car behind should also be within this angular range .phi..
For the driver to view the reflected image of the rear wheel and its vicinity, the door mirror should be tilted down through a predetermined angle from the mirror angle set for the ordinary driving of the car. Varying from one car model to another, the predetermined angle ranges from 5.degree. to 7.degree.. Concerning a certain car model, the predetermined angle is generally constant irrespective of the driver's sitting height.
Indeed in the conventional remotely controllable door mirror, the range of the mirror tilt by the drive unit can be increased so that the driver can get a vision of the rear wheel and its vicinity, but the following inconvenience remains in such case:
(a) If the adjusting range of the mirror angle is increased with the mirror tilt speed not changed, the time taken for the mirror operation is longer;
(b) If the mirror tilt speed is increased correspondingly to the increase of the adjusting range of the mirror angle, no accurate operation can be ensured in remote control of the mirror angle for the ordinary car driving; or
(c) Further in any of the above two cases, when a position in which the mirror angle is so set that the reflected image within the angular range .theta. shown in FIG. 3 can be viewed (which position will be referred to as "rear-viewing position for ordinary car drive" hereinafter) has been followed by a state in which the mirror angle is so set that the reflected image within the angular range .phi. shown in FIG. 3 can be viewed (which position will be referred to as "rear-viewing position for rear-wheel check" hereinafter) and further when the rear-viewing position for ordinary car drive is restored thereafter, the mirror is not in the rear-viewing position for ordinary car drive, thus causing an inconvenience because the mirror angle must be readjusted to set the mirror in the rear-viewing position for ordinary car drive.
The present invention has an object to overcome the above-mentioned drawbacks of the convention techniques by providing an electrical remote-control mirror assembly, which permits a quick and easy shift between the rear-viewing positions for ordinary car drive and rear-wheel check, respectively, without any influence on the operating accuracy of the remote control and ensures, because an mirror angle adjusted for the rear-viewing position for ordinary car drive is set as reference or initial angle, an accurate return to the initial position, namely, to the rear-viewing position for ordinary car drive when the remote control is operated for shift from the rear-viewing position for rear-wheel check to that for ordinary car drive.